/Engine/Source/Runtime/Core/Public/Misc/CoreDelegates.h
When a file is opened for read from a pak file.
static [TMulticastDelegate](API\Runtime\Core\Delegates\TMulticastDelegate)< void(const TCHAR *PakFile, const TCHAR *FileName), [FNotThreadSafeNotCheckedDelegateUserPolicy](API\Runtime\Core\Delegates\FNotThreadSafeNotCheckedDelegate-) > OnFileOpenedForReadFromPakFile;